Copper-Catalyzed Cascade Preparation of Dihydropyrimidin-4-ones from N‑(Prop-2-yn-1-yl)amides and Azides

Dihydropyrimidin-4-ones were efficiently synthesized from copper catalyzed reaction between N-(prop-2-yn-1-yl)­amides and sulfonylazides under mild conditions in moderate to excellent yields (up to 96% yields). The cascade process involves the copper-catalyzed alkyne–azide cycloaddition, the formation of ketenimine intermediate, the intramolecular nucleophilic addition of ketenimine, and subsequent rearrangement.

二氢嘧啶-4-酮（Dihydropyrimidin-4-ones）可由铜催化的N-(丙-2-炔-1-基)酰胺与磺酰叠氮之间的反应高效合成，反应在温和条件下进行，收率中等至优异，最高可达96%。该级联过程涉及铜催化的炔烃-叠氮环加成、烯酮亚胺中间体的形成、烯酮亚胺的分子内亲核加成以及后续的重排反应。